Punching-press



F. L. MORSE.

PUNCHING PRESS.

APPLICATION FILED OCTv I3. 1916. 1,809,907. Patented July 15, 1919.

4 SHEETSSHEET I. v

INVENTOR ATTORNEY F. L. MORSE.

PUNCHING PRESS.

- APPLICATION FILED 0CT.13. 1916. 1,309,907.. v Patented Ju1y15, 1919.

4 SHEETSSHEET 2.

INVENTOR F. L. MORSE.

PUNCHING PRESS.

APPLICATION FILED OCT-13.1916- Patented July 15, 1919.

4 SHEETSSHEET 3 I /I A TORNEY THE COLUMIHA PLANOGRAPH co., WASHINGTON, n. c.

ii a

- FRANK L. MORSE, or ITI-IACA, NEW YORK.

remains-mess.

Specification of Letters Patent.

Patented July 15, 1919.

Application filed October 13,1916. Serial No. 125,383.

To all whom it may concern Be it known that I, FRANK L. Monsn, a citizen of the United States, residing at Ithaca, in the county of Tompkins and State of New York, have invented a certain new and useful Improvement in Punching- Presses, of which improvement the following is a specification.

This invention relates to presses for punching or perforating metal plates and particularly for use in punching link plates and similar forms from a strip of sheet metal stock.

In presses as heretofore used for this purpose, wherein the ram or plunger carrying the punching tool is operated by the usual pitman mounted on an eccentric or crank, the pitman is so arranged on the eccentric as to hold the tool a little distance above the work, or strip of metal stock, at the upper end of its stroke, in order to provide suflicient clearance to shift the stock forward for the next stroke of the punching tool. As the eccentric then continues to rotate, the pitman begins to descend from its high point, but this movement starts slowly at first, and it is necessary for the eccentric to turn through a considerable arc, usually about ninety degrees, before the pitman descends a sufiicient distance to bring the punching tool in contact with the stock. At this instant the tool is moving downward at about its maximum rate so that it strikes the stock with quite a perceptible blow, and performs its punching action during an initial rapid and a gradually diminishing rate of movement. As the principal part of the shearing action of the metal takes place during the first part of the punching movement, this rapid action of the punch leaves the metal at the sheared surface in a rough and somewhat disintegral condition, and has a deteriorating effect upon the metal of the punch and of the die. It is well known in the art of metal punching that the wear of the punching tools and dies varies accordingly to the rate of movement of the punch during the shearing action, itb'eing much longer where the speed of the punch is slow during the shearing action than Where the punch moves at a comparatively high rate of speed. Under this action, the punching tool and die deteriorate rapidly and require frequent grinding, thus making the useful life of the same comparatively short.

The object of my invention is, therefore, to diminish the speed of the punch during the shearing action without reducing the rate of rotation of the eccentric or the number of punching operations during a given time unit, in fact, the rate of rotation of the machine may be increased without produc- 111g any injurious results, thereby reducing the cost and increasing the output, and at the same time, improving the character of the product and lengthening the life of the punches and dies.

Vith this object in view, my invention provides means for producing the shearing action by a slow initial and gradually increasing rate of movement of the punching tool during the first part of its stroke, and according to a preferred construction, it consists in providing a pitman and eccentric so arranged that the punching tool will engage the stock at the upper or outer end of the throw of the eccentric, thereby exerting its punching or shearing action with a slow initial movement which gradually increases, and means for separating the punching tool and stock a sufiicient distance to provide the desired clearance for feeding the stock for-- ward prior to the time that the pitman on the eccentric reaches the top or outer point of its movement.

In the accompanying drawings: Figure 1 is a side elevation of a punching press embodying my improvement; Fig. 2, a front elevation of same; Figs. 3, 1, 5 and 6, diagrams illustrating the position of the parts and of the punch and die at four different points in the cycle of rotation; Fig. 7 a side elevation of a machine having a modified form of mechanism for separating the die and stock from the punch, prior to the time that the eccentric reaches the outer end of its movement in each revolution; Figs. 8 and 9, detail views showing in side elevation and plan one of the rocker arms; and Fig. 10, a vertical section of the toggle joint of the pitman shown in Figs. 1 and 2.

According to the construction shown, the machine is of the usual form, comprising a base, 10, with the uprights, 11, carrying the bearings for the main shaft, 12, on which is fixed an eccentric, 13, for operating the pitman, 14, to actuate the slide, 15, and the punching tool. As heretofore used, the eccentric carrying the pitman has been so mounted as to raise the punching tool some distance above the stock, when at its high est point, but according to my improvement, the arrangement is such that at the highest point of the eccentric and pitman, the punching tool will engage the stock in readiness to make a punching action. At a point in the revolution of the eccentric prior to its highest position, means are provided for separating the punching tool from the stock a sufficient distance for the shifting of the stock freely forward from one position to the next.

As shown in Figs. 1 and 2, this means comprises a pit-man having a toggle joint inserted therein, and mechanism operating automatically to break said toggle and bend the joint of the pitman as the eccentric is moving upward from its lowest to its highest point. While various forms of mechanism may be employed for this purpose, I have shown a preferred construction, comprising a rock shaft, 16, mounted in the frame parallel with the shaft, 12, and carrying a rocker arm, 17, the upper end of which has a roller bearing against the cam, 18, on the shaft, 12, and the lower end being connected by a hook, 19, with the pin, 20, of the jointed pitman, 14:. As shown in Fig. 2, the cam, 18, is preferably double, one part at each side of the eccentric bearing, 21, of the pitman, and the rocker arm is bifurcated, as shown in Figs. 8 and 9, each part carrying a roller, 22, for engaging one portion of the cam, 18.

I The joint of the pitman is preferably constructed as shown more particularly in Fig. 10, the adjacent ends of the pitman sections having semi-cylindrical bearings upon opposite sides of the pin, 20, and tapered hub portions, 23, at both sides which are covered by the cylindrical caps, 24:, having correspondingly tapered sockets adapted to be drawn up on the hubs, 23, by the nuts, 25, threaded upon the ends of the pin, 20, outside of the caps. These caps thus serve to hold the two parts of the pitman together, and provide bearing surfaces for the joint upon the tapered portion of the hubs as well as upon the pin. By adjusting the nuts, 25, all wear may be taken up and the joint kept tight. The ends of the pitman are of course beveled ofl at 26, to allow clearance for movement when the joint bends. The lower section of the pitman is provided with a sliding joint, 14, to adjust the length of the same, and a ball and socket joint connection, 14, with the slide, 15, thereby providing for a free movement at this point. The slide, 15, is adapted to reciprocate vertically upon the guides, 33, supported on the frame.

The cam, 18, is so placed upon the shaft that the roller, 22, of the roc-kergarm, 17 engages the low point of the cam when the eccentric, 13, reaches its highest point, and the pitman is held straight by the link,'19, as indicated in Figs. 1 andt. The latter figure also shows the position of the punch,

withdraw the punch from the stock, leaving the same free to be shifted forward for the next punching operation. movement of the eccentric from this position 30,-as just in engagement with the stock, 31, on the die, 32, supported on the base,10, of the machine. As the shaft, 12, continues to turn in a clockwise direction, the eccentric begins to move downward, applying pressure to the punch, with a slow initial movement and a gradually increasing rate until the quarter point is reached, at which the punch has moved one-half of its down ward punching stroke. During this part of the movement, the major portion of the shearing action is performed, and the further movement to the bottom of the stroke pushes the blank into the die, as indicated in Fig. 5, the roller, 22, traveling on the low circular portion of the cam 18, and the pitman remaining straight during the half of the revolution of the shaft and eccentric.

As the shaft continues to rotate, the roller, 22, travels'up or out on the inclined portion of the cam surface to the high point, as indicated in Fig. 6, thereby turning the rocker arm, 17, on the shaft, 16, and by means of the link connection, 19, bending the jointed pitman. This action serves to promptly The further shown in Fig. 6, to a point near its highest position, indicated in Fig. 3, raises the punch still higher above the stock, thus affording greater clearance for the movement of the latter, and the pitman is still held in its bent position as the roller, 22, travels on the outer circular portion of the cam, 18.

During the movement from the position indicated in Fig. 6, to that shown in Fig. 3, the stock may be shifted or fed to a new position by the usual automatic feed mecha- V nism, (not shown), and as the eccentric passes the position shown in Fig. 3, the roller, 22, passes ofi from the outer curve and drops down the inclined surface to the inner curve in the position indicated in Fig. 4, as the 11 eccentric reaches its highest position and completes the revolution. This movement serves to straighten the pitman, and bring the punch down upon the stock in readiness to begin the next punching operation. Mere 1 gravity or weight of the parts may be sufli' cient to bring the same b-ack to the straightened position of the pitman, or a spring, (not shown), maybe employed to assist this action. Iprefer, however, to make this a positive movement by providing an addi tional cam, 28, on shaft, 12, with a corresponding roller, '29, and rocker arm,27, mounted on the shaft, 16, as shown in Fig. l. The cam, 28, is the reverse of the cam, 18,

so that the roller, 29, rides out from the.

inner curved surface of cam, 28, to its outer curved surface at the same time that the roller,.22, drops from the outer to theinner curved surface of cam, 18, thereby positively turning the shaft, 16, and actuating the pitman to its straight position, as indicated in Fig. 1. The pitman is thus alternately actuated to its bent position by the cam, I8, and to its" straight position by the cam, 28, and is held in both positions by the respective cams acting on. the rocker arms, 17 and 27.

Other forms of mechanism may be employed for obtaining a separation and clearance between the tool and stock during the upward or outward movement of the eccentric, and just prior to the time that the eccentric reaches its highest position, such as shown, for instance, in Fig. 7 Where. the plate, 10, supporting the die, is mounted to reciprocate in guides, 37, by means of toggle links, 36, actuated by an arm, 3'5', co'nnected by a rod, 34, with the arm, 17, of the rocker, 17 The remainder of the construction is similar to that of Figs. 1 and 2, with the exception that the toggle joint is eliminated from the pitman. V

The rocker arms, 17' and 27, are operated by the respective cams, 18 and 28, as before described, to hold the toggle straight during the rotation of the eccentric from its highest position, in which the punch engages the stock, as indicated in full lines, Fig. 7, through substantially one-half of a revolution, during which the punching action takes place, and then promptly bends the toggle links, as indicated in dotted lines, Fig. 7, to Withdraw the die from the punch, and afford a clearance for shifting the stock for the next punching operation, as will be readily understood. Then as the eccentric approaches its highest position, the toggle links, 36, are again straightened by means of cam, 28, arms, 27 and 17, and rod, 34-, thusbringingthe plate, 10, with the die and stock up into contact with the punch.

WVith both of the constructions shown, it will be observed that the punching tool makes contact with the stock at substantially the highest position of the eccentric; that the punching action starts with a slow initial and gradually accelerating movement, and that the punch is then quickly withdrawn or separated from the die and stock a sufficient distance to permit the stock to be readily shifted or fed forward to a new position for the next punching operation.

One great advantage derived from my improvement is that the rate of" movement of the punch during the initial shearing action is comparatively slow, thus reducing the wear on the punch and die, while these parts may be quickly separated after the shearing action is completed. The speed of the machine, and the output, may therefore be increased without increasing the rate of movement of the punch during the shearing action. i

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a punching press, the combination with a rotary shaft, an eccentric mounted thereon, a pitman connected to the eccentric, and a punch operated thereby, the arrangement of said parts being such that the punch engages the stock at substantially the highest position of the eccentric, of mechanism operating after the completion of the downward movement of the eccentric to separate the punch and stock to allow for the shifting of the latter.

2. In a punching press, the combination with a rotary shaft, an eccentric mounted thereon, a pitman connected to the eccentric, and a punch operated thereby, the arrangement of said parts being such that the punch engages the stock at substantially the highest position of the eccentric, of cam operated mechanism to separate the punch and stock to provide clearance for the shifting of said stock.

8. In a punching press, the combination with a rotary shaft, an eccentric mounted thereon, a pitman connected to the eccentrio, and a punch operated thereby, the arrangement of said parts being such that the punch engages the stock at substantially the highest position of the eccentric, of mechanism operating during the outward movement of the eccentric for separating the punch and stock to provide clearance for the shifting of said stock.

4. In a punching press, the combination with a rotary shaft, an eccentric mounted thereon, a pitman connected to the eccentric, and a punch operated thereby, the arrangement of said parts being such that the punch engages the stock at substantially the highest position of the eccentric, of a cam mounted on said shaft, a rocker arm actuated by the cam and mechanism operated by the rocker arm for withdrawing the punch to provide clearance for the shifting of the stock.

5. In a punching press, the combination with a rotary shaft, an eccentric mounted thereon, a pitman connected to the eccentric, and a punch operated thereby, the arrangement of said parts being such that the punch engages the stock at substantially the highest position of the eccentric, of a cam and connecting means operated thereby to separate the punch and stock to provide clearance for shifting said stock, and another cam and connections for bringing the punch and stock into engagement.

6. In a punching press, the combination of a rotary shaft, an eccentric, a reciprocating punch, a pitman driven by said eccentric for advancing and withdrawing said punch, said pitman being formed of relatively movable parts for varying the effective length of the same, and means operated by said shaft for alternately extending and contracting said pitman during its advance and return movement by the eccentric.

7". In a punching press, the combination of a rotary shaft, an eccentric, a reciprocating punch, a pitman driven by said eccentric for advancing and Withdrawing said punch, said pitman being formed of relatively movable parts for varying the eifective length of the same, and means operated by said shaft for holding said pitman extended during its advance movement by the eccentric.

8. In a punching press, the combination of a rotary shaft, an eccentric, a reciprocau ing punch, a pitman driven by said eccentrio for advancing and Withdrawing said punch, said pitman being formed of relatively movable parts having a toggle joint connection, and means operated by said shaft for alternately bending and straight ening the toggle joint during .the advance and return movement of the pitman by the eccentric.

9. In a punching press, the combination of a rotary shaft, an eccentric, a reciprocating punch, a pitman driven by said eccentric for advancing and Withdrawing said punch, said pitman being formed of relatively movable parts having a toggle joint connection,'m eans operated by said shaft for holding the toggle joint straight during the advance movement of the punch, and for bending the toggle joint during the return movement of the pitman by the eccentric.

10. In a punching press, the combination of a rotary shaft, an eccentric, a reciprocating punch, a pitman driven by said eccentric for advancing and withdrawing said punch, said pitman being formed of rela- Oopies of this patent may be obtained for a rocker arm actuated thereby, and a link" connecting said armwith the pitman to bend said toggle joint.

12. In a punching press, the combination of a rotary shaft, an eccentric, a pitman mounted on said eccentric and having a toggle joint, a rock shaft, a rocker arm thereon, a link connecting the same with the toggle joint, a cam on the main shaft for actuating said rocker arm, and another cam and rocker arm for actuating the rock shaft in the opposite direction.-

13. In a punching press, the combination with a rotary shaft, and an eccentric, of a pitman formed in two relativelymovable parts having hub portions at then adjacent ends, a pin forming a bearing between the said ends, and caps fitted over said hubs.

14. In a punching press, the combination with a rotary shaft, and an eccentric, of a pitman formed in tWo relatively movable parts having tapered hub portions at opposite sides of each of said adjacent ends of the parts of the pitman, caps having tapered sockets fitted over said hubs, and a pin forming a bearing between said ends and passing through said caps.

In testimony whereof I have hereunto set my hand.

FRANK L. MORSE.

five cents each, by addressing the Commissioner of 'Patents, Washington, .D. 0 

